No association between the -399 C > T polymorphism of the neuropeptide Y gene and schizophrenia, unipolar depression or panic disorder in a Danish population.

OBJECTIVE: A polymorphism in the promoter region of the NPY gene at position -399 C > T was recently reported to be associated with schizophrenia in a Japanese population and with treatment refractory unipolar depression in a Swedish population. The objective of this study was to investigate potential associations between the polymorphism and three psychiatric disorders in a Danish population. METHOD: We investigated the occurrence of the polymorphism in patients with schizophrenia (n = 291), unipolar depression (n = 256) and panic disorder (n = 142) compared with controls (n = 716). RESULTS: We detected the polymorphism -399 C > T at a frequency of 48% in controls. No significant differences were found between genotype or allele frequencies in controls vs. the patient groups. CONCLUSION: The lack of association between the -399 C > T polymorphism and schizophrenia, unipolar depression or panic disorder, respectively, suggests that the polymorphism is not involved in the etiology of these disorders in the Danish population.

Platelet serotonin transporter in stroke patients.

OBJECTIVES: Post-stroke depression can be treated with serotonin transport inhibitors suggesting a role for the serotonin system in these patients. The number of platelet serotonin transporters in stroke patients and in control subjects have been measured in this study. MATERIAL AND METHODS: Newly admitted stroke patients who did develop or who did not develop a post-stroke depression, non-acute patients who previously had had a stroke and control subjects were compared. The number of platelet serotonin transporters was analysed by ligand binding methodology. RESULTS: The number of platelet serotonin transporters was low shortly after a stroke compared with normal subjects; no difference was found between the stroke patients who developed a post-stroke depression and those who did not. CONCLUSION: A low number of platelet serotonin transporters may be a non-specific state marker for a condition as acute stroke.

Platelet serotonin transporters and the transporter gene in control subjects, unipolar patients and bipolar patients.

OBJECTIVE: The purpose of the present study was to relate the number of platelet serotonin transporters in unipolar and bipolar patients and in control subjects to two polymorphisms in the serotonin transporter gene: a VNTR in intron 2 and a deletion/insertion in the promoter region. METHOD: Density of platelet serotonin transporters was determined by radioligand binding analysis. Genotyping was performed by PCR amplification of polymorphic regions followed by size determination of the obtained fragments. RESULTS: The control subjects and the two groups of patients were similar with respect to the genotype and allele distribution belonging to the two polymorphisms in the serotonin transporter gene for. An interaction between status (control, unipolar- or bipolar patient) and VNTR genotype regarding the number of platelet serotonin transporters was observed; unipolar patients with the genotype 12/10 had more platelet serotonin transporters than bipolar patients and controls with this genotype. No association related to the polymorphism was found in the promoter region of the serotonin transporter gene. CONCLUSION: An association was observed between the polymorphism in intron 2 of the serotonin transporter gene and the number of platelet serotonin transporters. Unipolar patients with a particular genotype had more platelet serotonin transporters than the corresponding controls and bipolar patients.

Prophylactic efficacy of lithium administered every second day: a WHO multicentre study.

OBJECTIVES: To study the prophylactic efficacy of lithium administered every second day to patients with bipolar disorder or recurrent unipolar depressive disorder. METHODS: The study was carried out as a WHO multicentre study in five different psychiatric clinics: Russia (Moscow), Canada (Montreal), India (Lucknow), Germany (Munich) and South Korea (Pusan), with the lithium tablets being supplied from Denmark (Copenhagen). Participation in the study was conditional on the patient having been in prophylactic lithium treatment for the preceding 2-year period and having been free of depressive or manic phases during the preceding 6 months. After a 2-month baseline period during which lithium was administered every day, the treatment was changed to lithium intake every second day, this regimen in most cases being continued for 22 months. RESULTS: Forty-seven patients, 42 with a diagnosis of bipolar disorder and five with a diagnosis of recurrent unipolar depressive disorder, participated in the study. The number of patients from each centre ranged from six to 11. The mean lithium dose every second day was 36 mmol lithium, leading to a mean 12-h standard serum lithium concentration during the last month of treatment at 0.78+/-0.16 mmol/L. Lithium intake every second day was effective in 38 out of 47 patients. The remaining nine patients had recurrences, a number not differing from the 16 patients in the same group of 47 patients who, during the 2-year period preceding the study, had recurrences. The mean 12-h standard serum lithium concentration was lower in the patients who had recurrences than in those who stayed euthymic. The results suggest that to be effective when administered every second day, lithium must be given in a dose leading to a 12-h standard serum lithium concentration at 0.8 mmol/L or above. CONCLUSIONS: In the dose administered, lithium intake every second day was as effective as lithium intake every day. The amount and severity of lithium-related side effects were apparently not influenced by the change to lithium intake every second day.

Non-acetylcholine displaceable 3[H]epibatidine binding in the rat brain.

Using autoradiography two types of 3[H]epibatidine binding in rat brain was found, the by far most widespread was nicotine displaceable, and represented nicotinic cholinergic receptors, probably the two subtypes alpha4beta2 and alpha3beta4. Using acetylcholine and nicotine in concentrations able to displace 3[H]epibatidine from the alpha4beta2 and alpha3beta4 subunits, in a few brain structures a non-acetylcholine and non-nicotine displaceable 3[H]epibatidine binding was found. The binding was almost exclusively localised to the medial and lateral habenula, interpeduncular nucleus and pineal gland; at 0.1 nM 3[H]epibatidine it represented about 40% of the total 3[H]epibatidine binding. A literature search directed at neurotransmitters in habenula did not demonstrate any neurotransmitter with this anatomical distribution in the brain, suggesting that the non-acetylcholine displaceable 3[H]epibatidine binding represents a binding site, not previously described.

Prevalence of winter depression in Denmark.

An unselected cohort of 3556 subjects in Copenhagen was asked to complete the Seasonal Pattern Assessment Questionnaire (SPAQ) for estimating the presence of seasonal affective disorders (SAD or winter depression). Completed questionnaires were received from 1794 subjects in total. About 12% of the respondents had a Global Seasonality Score (GSS) high enough to indicate the presence of SAD. Among those respondents without SAD, women and younger people were found to be much more sensitive to seasonal and weather changes than men and older people, respectively.

An affinity-modulating site on neuronal monoamine transport proteins.

The dissociation rates of [3H]nisoxetine, [3H]GBR 12935 and [3H]citalopram from, respectively, the rat brain noradrenaline, dopamine and 5-HT transporters were found to be markedly affected by several drugs. Sertraline strongly attenuated the rate of dissociation of [3H]nisoxetine from the noradrenaline transporter, while citalopram strongly attenuated that of [3H]citalopram from the 5-HT transporter. The effect of both drugs were stereospecific. Less potent affinity-modulating drugs were identified with regards to [3H]GBR 12935 dissociation from the dopamine transporter. All three neuronal monoamine transporters may thus have specific affinity-modulating sites which change the function of the transporters with possible implication for the reuptake of monoamines released during synaptic activity.

Twelve-hour brain lithium concentration in lithium maintenance treatment of manic-depressive disorder: daily versus alternate-day dosing schedule.

The 12-h brain lithium concentration was measured by lithium-7 magnetic resonance spectroscopy in ten manic-depressive patients receiving daily or alternate-day lithium carbonate treatment. The median dose of lithium carbonate was 800 mg in the daily treatment group and 1200 mg in the alternate-day group. Median 12-h serum lithium concentration in the two groups was 0.86 mmol l-1 and 0.55 mmol l-1, respectively, while the corresponding concentration in brain was 0.67 mmol l-1 and 0.52 mmol l-1, respectively. The 12-h brain lithium concentration was independent of lithium dosing schedule (multiple linear regression), but correlated significantly with the 12-h serum lithium concentration (P = 0.003; B = 0.53, 95% c.l. 0.24-0.82; beta = 0.83). Thus at identical 12-h serum lithium concentrations the 12-h brain lithium concentration is similar with both treatment regimes. As the risk of manic-depressive relapse during alternate-day lithium treatment is in our experience 3-fold greater than with daily treatment (at similar mean 12-h serum lithium concentration), the findings suggest that the difference in the prophylactic efficacy of the two dosing schedules is unrelated to differences in the 12-h brain lithium concentration.

The influence of climate on development of winter depression.

126 patients suffering from winter depression participated in the study. Every second week patients completed the 13 item Beck Depression Inventory (BDI) in the period September to May in the years 1991 to 1994. Local weather data from this period were obtained from the Meteorological Institute, Copenhagen. No significant correlation was found between score on BDI and cloud cover, rainfall or atmospheric pressure. A significant correlation was found between score on BDI and minutes of sunshine, global radiation, length of daylight and temperature. This is in accordance with the theory, that lack of light is a contributing factor for development of winter depression.

Double-blind comparison of the side-effect profiles of daily versus alternate-day dosing schedules in lithium maintenance treatment of manic-depressive disorder.

The side-effect profiles of daily vs. alternate-day lithium carbonate dosing schedule were compared in a double-blind study of 50 manic-depressive patients. Following a 3-month period on daily lithium maintenance treatment the patients were randomly allocated to daily or alternate-day lithium dosing aiming at maintaining the same 12-h serum concentration as prior to allocation (median 0.7 mmol/l). The daily and alternate-day median lithium doses were 700 mg and 1200 mg, respectively. There was no significant correlation between changes in the side-effect scores on the UKU side-effect rating scale and lithium dosing schedule (ordinal logistic regression), although analysis revealed a trend in favour of alternate-day dosing with respect to polyuria/polydipsia and diarrhoea (loose stool). The study thus lends no support to the hypothesis that lithium-related side-effects can be diminished by extending the interval between lithium doses from 1 to 2 days.

Lithium prophylaxis of manic-depressive disorder: daily lithium dosing schedule versus every second day.

The prophylactic efficacy of lithium carbonate given every second day versus daily intake was compared in a double-blind study including 50 manic-depressive patients. The patients met the DSM-III-R criteria for bipolar disorder or depressive disorder; according to ICD-8 the patients fulfilled criteria for manic-depressive disorder: All patients had experienced at least 3 episodes of mania or major depression, and all had been euthymic for at least 4 months. The median doses of lithium carbonate given were 800 mg/day or 1200 mg/every second day corresponding to median 12-h serum lithium concentrations of 0.6 mmol/l or 0.7 mmol/l, respectively. Manic or depressive relapse was defined as DSM-III-R criteria for mania or major depression, and a score > or = 10 on the Bech-Rafaelsen Mania Scale or the Bech-Rafaelsen Melancholia Scale, respectively. The two treatment schedules were allocated at random. Using the Cox proportional hazard model for statistical analysis, the lithium dosing schedule of every second day did not maintain its prophylactic efficacy against recurrent episodes of manic-depressive disorder. The risk of relapse increased 3 times when the interval between intake of lithium was extended from 1 to 2 days.

Differences in brain 5-HT transporter dissociation rates among animal species.

The potential of using receptor-ligand dissociation rates as a model for investigating molecular changes in receptors was tested using the dissociation of [3H]citalopram, [3H]paroxetine and [3H]imipramine from the brain 5-HT transporter of four different species (mouse, rat, pig and man). Since the dissociation rates of each of the three ligands differed in most of the species investigated, receptor-ligand dissociation rate constants would seem to be a sensitive measure of receptor conformation. The model could be useful in the search of structural variation in receptors whether attributable to genetic factors or to posttranslational modification.

24-hour lithium concentration in human brain studied by Li-7 magnetic resonance spectroscopy.

Brain and serum lithium concentrations were measured every second hour during a 24-hr period following lithium intake, and again 48-hr later in two normal subjects in steady state lithium treatment receiving lithium carbonate (Priadel Synthelabo) once every evening. The brain-lithium concentration was measured by 7Li magnetic resonance spectroscopy (MRS). The brain lithium level was found to undulate in a peak-trough pattern that followed the serum lithium profile, although in an attenuated form. The brain/serum lithium concentration ratio varied considerably during the 48-hr period, ranging from 0.5 to 1.3, but the ratio was independent of the serum-lithium concentration. The median half-life for lithium was 28 hr in the brain, and 16 hr in serum. The brain lithium concentration in the morning was about 75% of the clinically relevant standard 12-hr serum lithium concentration. The finding that brain lithium undulates during the day means that MRS measurements of brain lithium can only be compared if carried out under standard conditions that include a fixed interval following lithium intake and an identical treatment regimen.

[Winter depression and light therapy]. / Vinterdepression og lysbehandling.

Winter depression (Seasonal Affective Disorder, SAD) is a depressive illness, which starts in the autumn and disappears in the spring. The depression is, in contrast to the typical endogenous depression, characterized by increased appetite with carbohydrate craving, and increased sleep. There is an increase in the frequency of the illness towards the geographical poles. About 80% of the patients are women. The most remarkable aspect of the depression is however, that it can be effectively treated with bright light, given two hours daily for one to two weeks. A number of biological functions are currently under investigation in relation to winter depressions; among these are the metabolism of melatonin, various diurnal rhythms and the serotonergic system.

Platelet paroxetine binding in depressed and nondepressed chronic pain patients.

Analysis of 3H-paroxetine binding was used to determine the number of serotonin transporters in platelet membranes of chronic pain patients and controls. The pain patients who also suffered from depression in addition to the pain had significantly more serotonin transporters than the controls.

Brain 5-HT1A, 5-HT1D, and 5-HT2 receptors in suicide victims.

We report on 5-HT1A, 5-HT1D, and 5-HT2 binding sites in 23 control subjects and 18 suicide victims subdivided according to the method of death and the previous existence of depressive symptoms. No difference in maximum binding (Bmax) or binding affinity (Kd) was found between the control and overall suicide groups for the binding sites studied. The drug overdose subgroup showed, however, a significant decrease in the 5-HT1A binding affinity, probably explained by the higher sensitivity of this binding site to the acute administration of tricyclic antidepressants. A significant decrease in 5-HT1D binding affinity was also found in the depressed suicides, together with a significant decrease in the number of 5-HT1D binding sites in the nondepressed suicides. Further studies should be carried out on the 5-HT1D binding site as it might represent a new tool in the understanding of the depressive illness.

Platelet paroxetine binding and light therapy in winter depression.

The effect of light therapy on serotonin uptake capacity in patients suffering from winter depressions (seasonal affective disorders) was examined indirectly by using [3H]paroxetine binding to determine the number of platelet serotonin transporters. In patients who responded to light therapy the number of platelet serotonin transporters decreased significantly following treatment. In contrast, patients who did not respond to light therapy were found to have a relatively low number of serotonin transporters prior to treatment, and the number did not change significantly following treatment.

Effect of aging in human cortical pre- and postsynaptic serotonin binding sites.

5-HT1A, 5-HT1D, 5-HT2 binding sites and affinity and 5-HT uptake sites were simultaneously determined in frontal cortex samples from 23 control subjects, aged 16-75 years. A significant reduction in the number of 5-HT1D and 5-HT2 binding sites was found with regard to age, together with a significant decrease in the 5-HT2 binding affinity. It is suggested that the total 5-HT1 age-related loss described in previous studies could be ascribed to the 5-HT2 subtype. Furthermore, aging does not seem to be associated with a reduced cortical serotonergic innervation, as indicated by the stability of the [3H]paroxetine-labeled 5-HT uptake sites.

Platelet paroxetine binding in alcoholics.

Platelet paroxetine binding was analysed in 24 abstinent alcoholics and 18 control persons. The alcoholics had significantly more binding sites than the control persons. Most of the alcoholics showed affective symptoms and the increased platelet paroxetine binding was predominantly observed among those who had the lowest Newcastle score, indicating the presence of non-endogenous depression.